Safety valve device



Sept. 10, 1935. P. H. HAMILTON I 2,013,713

' SAFETY VALVE DEVICE Filed May 16, 1952 kass 5.5 46 A n 45 .56 W

AT-roqwzzs I Patented Sept. 10, 1935 PATENT OFFICE SAFETY VALVE DEVICEPaul H. HamiltomCleveland, Ohio, assignor to The SandsManufacturing'company, Cleveland, Ohio, a corporation of OhioApplication May l6, 1932, Serial No. 611,583 9 Claims. (Cl. 236-21) Thisinvention relates to safety valve devices, and particularly to safetyvalve devices for controlling the supply of fuel to a gas burner, andthe principal object of my invention is to provide a new and improveddevice of this type.

In the drawing accompanying this specification and forming apart of thisapplication, I have shown, for the purpose of illustration, one formwhich my invention may assume, and in the drawing:

Figure 1 is a perspective view,with parts broken away, of a heaterembodying my invention,

Figure 2 is a vertical sectional view of a safety valve mechanism forcontrolling the supply of fuel to the burner of the heater,

Figure 3 is a horizontalsectional view taken on line 33 of Figure 2,

' Figure 4 is a vertical sectional view taken on line 4-4 of Figure 2,while Figure 5 is a fragmentary elevational view of the latch mechanismillustrated in Figure 3.

Referring to the drawing, and in particular to Figure 1 thereof, myinvention is shown as being embodied in a hot-water heater comprising acylindrical casing I, supported by legs 2 and divided by means of apartition 3, into an upper water chamber 4 and a lower combustionchamber 5. A substantially tubular centrally disposed pipe or flue 6communicates with the combustion chamber 5 and extends verticallythrough the water chamber 4, for permitting the products of combustion,generated in the combustion chamber 5, to escape to the outeratmosphere.

A substantially annular burner l is provided in the combustion chamber 5and is supplied with fuel, such as gas, through a vertically extendingpipe 8, which communicates at its upper end with a valve device 9. Thevalve device 9 is substantially similar to that disclosed in mycopending application for Letters Patent Serial Number 600,592, and iscontrolled by a thermostat lll which is responsive to the heat generatedby the main burner 1, and also by a pilot burner ll associatedtherewith. A pipe l2 establishes communication between the valve 9 andthe lower end of a valve l3 which is controlled by a thermallyresponsive device l4 extending into the water chamber 4; This valve isnormally main-. tained in an open position and is only closed when thetemperature of the water in the 'chambel 4 reaches a predeterminedmaximum degree. A, vertically extending pipe l5 communicates at itslower end with the pipe l2, through the valve l3 and the passage of fuelthrough the pipe 12 is also controlled by a manually operable valve l6.

A by-pass pipe ll communicates at its upper end with the pipe 15 on thefuel supply side of the valve [6, and at its lower end with the pilotburner H. The upper end of the pipe 15 communicates with the lower endof a normally open safety 5 valve device I8, which in turn communicateswith the lower end of a pipe l9, leading to a source of fuel supply, andwhich is controlled by a ther'- mally responsive device 53 projectinginto the upper portion of the chamber 4.

The safety valve device l8 preferably comprises a casting 20 providedwith a fuel inlet chamber 2!, which communicates with the pipe I!) andwith a fuel outlet chamber 22 which communicates with the pipe I 5.Communication between the chambers 2|v and 22 is at times establishedthrough a passageway 23, provided in a vertically extending wall 24, andwhich is surrounded by an annular valve seat 25 for cooperation with avalve member 26 carried by a valve stem 21. Access to the chamber 22,and to the valve member 26 disposed therein, may readily be obtainedthrough an opening 28 which is normally closed by a movable screw plug29. The valve stem 2? extends through the inlet chamber 2| and through asuitable packing gland 30 carried by the casting 29, and through abearing portion 3| which is integrally connected to the casting 20 inspaced relation thereto, by a boss 32, and is prevented from rotating bya screw 33 which is-30 threaded into the bearing 3| for slidingengagement with a key-way 34 formed in the valve stem 21. The outerendof the valve stem 21 is provided with a knob or handle 35,'by means ofwhich the valve stem 21 may be shifted inwardly 35 in order to open thevalve member 26, as will hereinafter be described. A coil spring 36 isinterposed between a bearing 3| and the knob 35, for urging the valvemember 26 into-seating engagement with its cooperating valve seat 25.

The valve member 26, of the safety .valve device IB, normally occupiesan open position so as not to interrupt the supply of fuel to theremainder of the apparatus, but is under the control of the thermallyresponsive device 53, whereby 45 the flow of fuel to the burner may beinterrupted in the event of abnormaloperation. This thermally responsivedevice 53 preferably comprises a tube 31 formed of a metal, such ascopper, having a relatively high coefficient of expansion when subjectedto heat, one end of which is threaded into a bore 38 provided in theboss 32, and which extends into the upper portion of the chamber 4.Extending entirely through the tube 31 is a rod 39, formed of materialhaving a 55 I relatively low coefiicient of thermal expansion,

' such as invar or the like, the inner end of which is suitably securedto the inner end of thetube 31, and the outer end of which is threadedinto a shell 40 disposed within the bore 38 for telescopic engagementwith the end ofthe tube II. A cap 4| is threaded onto the inner end ofthe tube 31 so as to. prevent leakage of water into the tube at thispoint.

Slidably mounted inthe shell 4| is a detent or pin 42 which-is providedwith a head 43 for engagement with ashoulder 44, to prevent thedisplacement thereof, and which is yieldably urged outwardly by acoilspring 45 interposed between the head 43 and the adjacent end of the rod39. v

Under normal operating conditions, the pin 42 engages behind an annularshoulder 45 formed eccentrically on the collar 41, which is carried bythe valve stem 21 and whichis maintained in adjusted position thereon bya set-screw 48. However, if the temperature of the water in the chamber4 should reach a predetermined maximum, the expansion, and consequentelongation, of the tube 31 will draw the rod-39 inwardly, to the righhasviewed in Figure 3, thus disengaging the pin 42 from the shoulder 46 andpermitting the valve member 26 to close under the action of the spring36.

As soon as the abnormal conditions which caused the operation of thesafety valve device have been corrected, and the tube cooled andcontracted to its normal length, the valve member 26 may be opened so asto reestablish communication between the burner and its directlyassociated parts and the source of fuel supply,

by manually shifting the valve stem 21 inwardly against the action ofthe spring 36. This movement of the valve stem 21 carries a bevelledportion 49 of the shoulder 45 into engagement with packing member 5|,which is secured in position by means of screws 52 and which excludesforeign matter from the detent 42 and associated mechanism;

The thermally responsive device I4 is initially adjusted so as to closethe .valve I3 and interrupt the supply of fuel to the burner I when thetemperature of the water reaches a predetermined degree, 200 forexample. The thermally responsive device 53, however, of the safetyvalve device I8 is initially adjusted to close the valve 26 when thetemperature of the water reaches a predetermined'higher maximum degree,212

' F., for example. Under normal operation, the

thermostat i4 will control the supply of fuel to dlscontinueithe supplyof fuel to the entire apparatus. -Thus, 'it will be apparent that thevalve device 18 functions as a safetymeasure in the-event that the valvei3 and associated therresponsive means.

perature as which the thermally responsive device 53 will release thevalve 26 may be regulated by means oi the eccentric shoulder 44. This isaccomplished by screwing the set-screw 40 and rotating the collar 41 onthe valve stem 21, so 5 as to increase or decrease the degree of overlapbetween the shoulder 45 and the detent 42. If the collar 41 is rotatedso that the detent 42 overlaps the shoulder 48 a relatively smallamount, a release will be effected by a relatively small amount ofexpansion of the tube 31. 0n the other hand, if the collar 41 isadjusted so as to provide a relatively large amount of overthere isprovided a secondary control for the fuel 25 supply to the burner whichonly functions in the event that the main fuel control functionsimproperly, or not at all, thus materially reducing the possibility ofdanger resulting from-an excessive rise of temperature, or undue steampressure developed within the water chamber 4.

It will be obvious to those skilled in the art, that the embodiments ofmy invention herein shown and described may be variously changed, used,or modified, all without departing from the 35 spirit of my invention orsacrificing the advantages thereof, and it therefore will be understoodthat the disclosures herein are illustrative only, that my inventionembodies advantages and uses other than those particularly pointed outor sug- 4o gested herein, and that my invention is not limited thereto.

I claim:

. 1. A device of the character described, comprising: a burner and aconduit leading to said burner; a first valve interposed in said conduitand responsive to the temperature of a locality heated by said burnerfor controlling the supply of fuel to said burner; a second valveinterposed in said conduit and having means responsive 50 to thetemperature of said locality for automatically interrupting the supplyof fuel through said conduit and to said first valve, when saidtemperature reaches a predetermined maximum, said second valve when infuel interrupting po- 55 sition being non-cooperative with respect tosaid responsive means; and manually operable means for actuating saidsecond valve to reestablish the supply of fuel through said conduit andto said first valve.

2. A device of thecharacter described, comprising: main burner and aconduit leading to said burner; a pilot burner associated with said mainburner; a first valve interposedin said conduit and responsive to thetemperature of a lo-' cality heated by said main burner for controllingthe supply of fuel to said main burner-only; and a second valveinterposed in said conduit and having means responsive to thetemperature of the same locality for interrupting the supply 'of fuelboth to said main burner and to said pilot burner at a predeterminedtemperaturqpand said second valve when in fuel interrupting positionbeing non-cooperative with respect to said 3. A device of the characterdescribed, comprising: a main burner and a conduit leading to saidburner; a pilot burner associated with said main burner; a first valveinterposed in said conduit and responsive to the temperature of alocality heated by said main burner for automatically interrupting thesupply of fuel to said main burner only, when said temperature reaches apredetermined maximum degree, and for automatically establishing thesupply of fuel to said burner when said temperature is below saidmaximum degree; a second valve interposed in said conduit and havingmeans responsive to the temperature of said locality for automaticallyinterrupting the supply of fuel both to said main burner and to saidpilot burner when said temperature reaches a predetermined maximumdegree, said second valve and said responsive means beingnon-cooperative when said second valve is in fuel interrupting position;and manually operable means for actuating said second valve toreestablish the supply of fuel to said main burner and said pilotburner.

4. A device of the character described, comprising: a burner; a valvefor controlling the supply of fuel to said burner; a spring means foryieldably urging said valve toward a closed position; a shoulderedmember movable with said valve; a detent engageable by said member forholding said valve open against the action 0. said spring; meansresponsive to the temperature of a locality heated by said burner foractuating said detent to release said shouldered member and to effectthe closing of said valve; and manually operable means for opening saidvalve against the action of said spring and for simultaneously movingsaid member into operable enher and to effect the closing of said valve:means.

for adjusting said shoulder relative to said detent to efiect suchrelease at different temperatures; and manually operable means foropening said valve against the action of said spring and forsimultaneously moving said member into operable engagement with saiddetent.

6. A device of the character described, comprising: a burner; a valvefor controlling the supply of fuel to said burner; a spring foryieldablyurging said valve toward a, closed position; a member movable with saidvalve and provided with an eccentric shoulder; a detent engageable bysaid shoulder for holding said valve open against the action of saidspring; means responsive to the temperature of a locality heated by saidburner for actuating said detent to release said valve; said shoulderbeing rotatable to effect adjustment with respect to said detent to 5cause said valve to respond at a selected temperature.

7. A device of the character described, comprising: a burner, a valvefor controlling the supply of fuel to said burner, a spring for yield-10 ably urging said valve. toward a closed position;

a shouldered member movable with said valve; means responsive to thetemperature of a, locality heated by said burner carrying a yieldabledetent for operable engagement with said shouldered 15 member, saidyieldable detent engaging said shouldered member and holding said valveopen, and releasing said shouldered member at a predeterminedtemperature to eii'ect closing of said valve; and means for opening saidvalve against 2 the action of said spring and for simultaneously movingsaid shouldered member into operable engagement with said detent.

8. A device of the character described, comprisingi a burner; a valvefor controlling the 25 Y supply of fuel to said burner; a spring foryieldably urging said valve toward a closed position; a shoulderedmember movable with said valve and provided with a chamfered surface; ayieldoperable means for opening said valve against 35 the action of saidspring and for simultaneously moving said chamfered surface past saidyieldable detent and causing said shoulderedmemher to engage saiddetent.

9. A valve, comprising: a valve casing pro- 40 vided with a walldividing said valve casing into a valve chamber and a valve actuatingchamber; a valve stem passing through saidwall in fluid tight relationand having one portion disposed within said valve chamber and another 5portion passing through said valve actuating chamber and extendingoutwardly of said valve casing; a valve aflixed to the portion of saidvalve stem which lies in said valve chamber and adapted to cooperatewith a valve seat formed therein; a spring aiiixed to the portion ofsaid valve stem which extends outwardly of said valve casing to urgesaid valve to a closed position; a shouldered member aflixed to theportion of said valve stem lying within said valve actuating chamber;and thermal means engaging said shouldered member to hold said valveopen against the action of said spring, and affected by a change intemperature to release said shouldered member and thereby cause saidvalve to close.

PAUL H. HAMILTON.

